Cell Structure and Function

Cell Structure

• Plasma membrane: thin layer of lipid and protein molecules that surrounds the cell
• Cytoplasm: jelly-like substance inside the cell membrane where metabolic processes take place
• Nucleus: control center of the cell where DNA is stored
• Mitochondria: organelles responsible for generating energy for the cell
• Endoplasmic reticulum: network of membranous tubules and cisternae involved in protein synthesis and transport
• Ribosomes: small organelles found throughout the cytoplasm where protein synthesis takes place
• Lysosomes: membrane-bound sacs that contain digestive enzymes and help break down waste and foreign substances
• Golgi apparatus: complex of flattened sacs and tubules that process and modify proteins and lipids

Cell Functions

• Metabolism: cells carry out various chemical reactions to maintain homeostasis and energy production
• Growth and Development: cells divide and differentiate to form new tissues and organs
• Response to Stimuli: cells respond to internal and external stimuli to maintain homeostasis
• Reproduction: cells reproduce to produce new cells and maintain tissue integrity
• Waste Management: cells remove waste products and recycle nutrients

Cell Types

• Prokaryotic cells: lack a true nucleus and are typically small and simple in structure (e.g., bacteria)
• Eukaryotic cells: have a true nucleus and are typically larger and more complex in structure (e.g., plants, animals, fungi)

Cell Division

• Mitosis: process of cell division that results in two daughter cells with the same number of chromosomes as the parent cell
• Meiosis: process of cell division that results in four daughter cells with half the number of chromosomes as the parent cell (occurs in gamete formation)

Cell Communication

• Signaling pathways: mechanisms by which cells communicate with each other through molecular signals
• Cell adhesion molecules: molecules that help cells stick together and maintain tissue structure

Cell Structure

• Plasma membrane structure: phospholipid bilayer with embedded proteins, regulating what enters and leaves the cell
• Cytoplasm functions: site of metabolic processes, including glycolysis, citric acid cycle, and fatty acid synthesis
• Nucleus components: double membrane (nuclear envelope), nucleolus, chromatin, and nucleoplasm
• Mitochondria features: inner membrane (cristae), matrix, and intermembrane space, generating ATP through cellular respiration
• Endoplasmic reticulum functions: protein synthesis, lipid synthesis, and detoxification
• Ribosomes structure: large and small subunits, site of protein synthesis
• Lysosomes contents: digestive enzymes (e.g., acid hydrolases), breaking down waste and foreign substances
• Golgi apparatus functions: protein modification, lipid synthesis, and vesicle formation

Cell Functions

• Metabolic processes: glycolysis, citric acid cycle, electron transport chain, and fermentation
• Cell growth and development stages: interphase, mitosis, and cytokinesis
• Cellular responses: sensory perception, signal transduction, and effector response
• Reproduction mechanisms: mitosis, meiosis, and binary fission
• Waste management processes: autophagy, exocytosis, and apoptosis

Cell Types

• Prokaryotic cell features: single circular chromosome, no true nucleus, peptidoglycan cell wall
• Eukaryotic cell features: linear chromosomes, true nucleus, and diverse cell walls (e.g., plant cell walls)

Cell Division

• Mitosis stages: interphase, prophase, metaphase, anaphase, telophase, and cytokinesis
• Meiosis stages: interphase, prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II, and telophase II
• Meiosis outcomes: four haploid daughter cells, genetically unique and diverse

Cell Communication

• Signaling pathway types: endocrine, paracrine, autocrine, and synaptic
• Cell adhesion molecule types: integrins, cadherins, and selectins, involved in cell-cell interactions and tissue structure